Miniature electron tube stage assembly



Feb. 9, 1954 sH p o 2,668,933

MINIATURE ELECTRON TUBE STAGE ASSEMBLY Filed May 25, 1951 IN VEN TOR ausrA v5 SHAP/RO %UQ/3 62 75 16mm ATTORNEYS Patented Feb. 9, 1954 MINIATURE ELECTRON TUBE STAGE ASSEMBLY Gustave Shapiro, Washington, D. 0., assignor to the United States of America as represented by the Secretary of the Navy Application May 25, 1951, Serial No. 228,345

7 Claims.

(Granted under Title 35, U. S. Code (1952),

sec. 266) This device relates to the construction of a subminiature electron tube circuit, and more particularly to the physical arrangement of components in a single subminiature electron tube stage and the interconnection of a-plurality of these stages.

Miniaturization of electronic circuits, due to advances in electronic technology providing complex and extensive circuitry for multicapacity functions, has become increasingly important, especially where the size and weight of the devices is limited, such as in aircraft installations. The devices as taught by the prior art have generally involved a miniaturization of the circuit components, and a mounting and wiring of these miniature elements on a single rigid chassis, or in effect the application of standard techniques of electron tube circuit construction utilizing miniature electrical components and tubes.

. These circuits have in many instances been unsatisfactory, involving crowded components, thermal overheating, poor electrical shielding, and undesired interaction between circuits.

The present device, in order to correct for the above-mentioned defects, provides a series of in dividual electron tube circuit stages, each stage including a subminiature electron tube and subminiature electrical elements mounted within and shielded by its own individual chassis. These individual chassis being adapted to be of minimum size and weight for the stage while allowing ease of circuit component assembly, repair, and replacement, and providing structural rigidity, good electrical stability and good thermal conduction for all components mounted thereon. A series of these individual stages may be compactly stacked adjacent each other and serve to support and reinforce each other to provide an electrically stable multistage circuit wherein the ture electron tube circuit stage which is rigid,

light in weight, and occupies a minimum volume.

A further object of this invention is to provide an individually constructed subminiature electron tube circuit stage being compact, rigid, and

electrically and thermally stable during high frei a se g s ei e- A further object of this invention is to provide a series of individually constructed light weight subminiature electron tube circuit stages adapt ed to compactly nest together permitting ease of stage assembly, repair, or replacement.

A further object of this invention is to provide a series of electrically interconnected individually constructed subminiature electron tube circuit stages adapted to compactly nest together and provide substantially complete shielding and minimum stage interaction for all multi-stage components and connecting lines.

Still another object of this invention is to provide a series of individually constructed subminiature electron tube circuit stages adapted to compactly nest together and capable of being mechanically interconnected by the interstage electrical means.

A further object is to provide a nesting array of self-supporting subminiature electron tube circuit stages adapted to be mounted between additional shielding and supporting members.

Other objects and features will be readily apparent to those skilled in this art during the course of the following description, taken in connection with the accompanying drawings forming a part of this specification.

Fig. l and Fig. 2 are an exploded isometric view and an assembled isometric view respectively, of the physical arrangement of subminiature electrical components in a single electron tube circuit stage forming a preferred modification of the invention;

Fig. 3 is a skeleton side elevational view of three interconnected electron tube stages in which the subminiature tube and electrical elements have been omitted, and representing the nesting efiect of the stage chassis; and

Fig. 4 is a top plan view of the elements of Fig. 3 with the addition of side members.

Referring now to Fig. 1 showing an exploded isometric view of a single subminiature electron tube stage including a subminiature electron tube, a plurality of subminiature electrical elements and an individual stage chassis, and showing the relative positioning of the tube and components with respect to the chassis, all constituting a preferred embodiment of the invention, numeral It designates the individual stage chassis which comprises a three-sided sheet material enclosing member being substantially U-shaped in cross section and formed of a light, thin, material having high electrical and thermal conductive properties. Designating the substantially parallel surfaces [3 of the U-shaped member as the chassis sides and the base of the U-shaped member as ace- .9.

fingers I 3' alongthe upper andlower sides of the chassis make good electrical and thermal contact with succeeding metal circuit enclosing members 34, 35 and therefore additionally provide better heat dissipation and grounded electrical connection for the individual stages.

Fig. 3 is a skeletonized side elevation view of a plurality of the above-mentioned stage chassis, illustrating the manner in which they are combined in a multistage electronic circuit. The

stage components, including the subminiature electron tube and complementary electrical ele ments, have been omitted to simplify this illustration. As each of the stage chassis forms a three-sided enclosing member, a combination of,

these stages in linear arrangement provides a socalled nesting interaction, that is the rear portion of a preceding stage chassis provides with the three enclosing sides of a succeeding stage chassis an isolated semi-enclosure as may be seen from Fig. 4. Due to all stage components being held within the three sides of this succeeding stage chassis as shown in Figs. 1 and 2, the compartmenting action substantially provides the electrical hielding for the stage components. Lengthening the fingers of sides [3 so that they make electrical contact with 'an adjacent stage provides a completely electrically shielded compartment. The electrical interstage connection in the completed multistage circuit is permitted through these compartments by the opening iii, in the lower back portion of each stage chassis, as shown by Figs. 1 and 2, allowing wiring 32 to pass therethrough to adjacent stages. Further electrical interstage connection is made above and below both ends of the individual stage chassis on either side of the extending portions I I and ll-a, as may be seen by reference to Figs. 2 and 4, for wires designated 33 and 3|. It is to be understood that interstage electrical elements may be employed for decoupling or other electrical functions in place of wire 33, within the space provided by the nested stage chassis.

Fig. 4 is a top view of the linear array of stage chassis of Fig. 3 sandwiched between two elongate planar conducting members 34 and 35. The stage chassis slotted sides l3 engaging these planar members to permit electrical, thermal, and mechanical connection thereto, and completing the compartmenting of the stages as shown.

In the multistage circuit as illustrated by Figs. 3 and 4 in skeleton form, there is no necessity for mechanically interconnecting the plurality of stage chassis members during assembly, as the interstage electrical wiring 3|, 32, and 33 provides sufficient rigidity for fastening these light weight subminiature lectron tube stages together. Common electrical and thermal grounding of these stage chassis is provided by the planar members 34 and 35 described above and more fully disclosed in the copending application Number 228,344, filed May 25, 1951, by Robert K-F Scal, entitled Support and Housing Electronic Circuits.

Summarizing, the above device presents a subminiature electron tube and plurality of complementary electrical elements interconnected to form a single stage of a given type for functioning as one unit of a multistage complex circuit, in which the tube and elements for each stage are compactly mounted thermally bonded and electrically shielded by an individual chassis member. This form of individual stage construction occupies a minimum of volume and weight while providing rigidity, electrical shielding, and

a thermal conduction path for all stage components including the electrical interconnecting lines. The manner of stage construction and component assembly permits a compact interconnection of a plurality of stages in a novel nesting manner eliminating the need for a single overall chassis mounting member common to all stages, and permitting a multistage unit of reduced volume, light weight, rigid construction, ease of circuit assembly, and ease of stage replacement or repair. Various changes may be made by those skilled in the art throughout this device in accordance with the teachings herein, and accordingly, the above disclosed device is to be considered merely as a preferred embodiment of the teaching, while the invention is to be limited only by features as set forth in the claims. The invention described herein may be manufactured and used by or for the Government of the United States of America for governmental purposes without the payment of any royalties thereon or therefor.

What is claimed is:

1. A mounting, shielding, and heat conducting member for a subminiature tube and electrical 'elernent single stage circuit comprising a three sided, elongate chassis of sheet metal, having a substantially U-shaped cross section, the sides of the chassis transversely along the upper part being regularly slit to provide electrical grounding fingers and heat conducting fins while along the lower part being irregularly slit to provide holding means for subminiature electrical components, the chassis side junctions in cross section being rounded and extending outwardly from the sides to provide semicylindrical spaces for longitudinally housing subminiature tubular electrical elements, and a longitudinal holding means provided within the chassis enclosure for removably fastening a subminiature electron tube, whereby the volume enclosure formed by the three sided chassis body substantially encircles all the stage components.

2. In a multi-stage electron tube circuit assembly, a plurality of separate stage chassis each comprising a three-sided member having a U- shaped cross-section, chassis side junctions in cross-section being rounded and extending outwardly from the sides to provide semicylindrical spaces for longitudinally housing subminiature tubular electrical elements, the stage chassis in cascaded array having the rear side of a preceding chassis substantially completing the enclosure formed by the three sides of a succeeding chassis whereby the electrical components of each stage may have all sides compartmented by two adjacent chassis members thereby providing substantially complete electrical shielding for each stage.

3. A multistage circuit assembly of the type of claim 2 enclosed within a housing, said housing including two planar conducting surfaces contiguously engaging the opposite sides of each stage chassis and providing structural reinforcement for the cascaded array, complete shielding and grounding, and thermal cooling for all stages.

4.. A plurality of like individual electrical chassis members, each comprising a three-sided elongated member of U-shaped cross-section, the members positioned in cascaded array forming a series of semienclosures, a housing including two planar conducting surfaces for enclosing the cascaded chassis by aligning opposite sides of all the chassis members between the planar surfaces and contiguous therewith. thereby forming a 

